The present invention is directed to micro or nanostructures and their applications. More particularly, the present invention provides methods and resulting structures for forming molecular probes onto nano and micro structures for a wide variety of applications. As merely an example, such molecular probes have been used in life science applications. Accordingly, the present invention can enable researchers and scientists to identify promising candidates in the search for new and better medicines, for example, in screening, therapeutics, drug discovery, and development. But it would be recognized that the invention has a much broader range of applicability. The present invention may be used for other applications such as biochemical, electronics, chemical, medical, petrochemical, security, business, and the like.
Over the years, microelectronics have proliferated into many aspects of modern day life. In the early days, Robert N. Noyce invented the integrated circuit, which is described in “Semiconductor Device-and-Lead Structure” under U.S. Pat. No. 2,981,877. Integrated circuits evolved from a handful of electronic elements into millions and even billions of components fabricated on a small slice of silicon material. Such integrated circuits have been incorporated into and control many conventional devices, such as automobiles, computers, medical equipment, and even children's toys. Although the integrated circuit has been highly successful, there is still a need for developing other types of technologies for other applications. An example of such technology includes molecular electronics.
Molecular electronics constitutes an area of research in which molecular components are incorporated into electrical devices. Additionally, the characteristics of those electrical devices are altered in what are often interesting and useful manners by those molecules. Certain examples of molecular electronics exist. One example includes molecular electronic random access memory circuits. See, Yi Luo, C. P. Collier, Kent Nielsen, Jan Jeppesen, Julie Perkins, Erica Delonno, Anthony Pease, J. Fraser Stoddart, and James R. Heath, “Molecular Electronics Random Access Memory Circuits,” Chem Phys Chem 2002(3), 519 (2002). In such example, a bistable molecular switch has been exploited as a mechanism for storing ‘1’s and ‘0’s. While this circuit operates in a manner that is similar to a more conventional random access memory circuit, it has the advantage that switching characteristics arise from a molecular property, and so, in principle, individual memory element within the circuit should scale to the dimensions of a few molecules.
Another example is a molecular rectifier. See, A. Aviram and M. Ratner, “Molecular Rectifiers,” Chem. Phys Lett., 1971; R. M. Metzger, et al., J. Phys. Chem. B107, 1021 (2003). The molecular rectifier in which current rectification, or diode character, is built into a device through control of the molecular component. Yet another example is a nanowire molecular or biomolecular sensor. See, Yi Cui, Qingqiao Wei, Hongkun Park and Charles M. Lieber, “Nanowire nanosensors for highly sensitive and selective detection of biological and chemical species,” Science, 293, 1298 (2001). If the nanowire is sufficiently small (1 to 30 nanometers in diameter), then the electrical properties of the nanowire depend not just on the materials construction of the nanowire, such as doping level, physical dimensions, etc., but also on the chemical environment surrounding the nanowire Thus, the nanowire can also serve as a chemical sensor. Such a nanowire sensor can be customized for certain sensing tasks by chemically coating the surface of the nanowire with a molecular probe, such as an antibody for some molecular target, such as a particular protein. When the nanowire is exposed to a solution containing that protein, the protein binds to the nanowire sensor surface by binding to the antibody. The chemical environment surrounding the nanowire is modified by this target/probe binding event, and thus so are the electrical properties of the nanowire. Thus, the presence of the protein may be detected. Although molecular electronics have been successful, there are still many limitations.
From the above, it is seen that improved techniques for manufacturing molecular electronics and applications are highly desirable.